About 4 years ago I bought a pair of Siren Ventilator shoes from Merrell. They have been superb; very comfortable and hardwearing. This model has been replaced with Siren Breeze, a pair of which I bought this week. I would recommend the footwear without hesitation. I was undecided as to whether to purchase size 41 or 42 so bought both and returned the unwanted pair. The returns process was straightforward.I kept the size 41 which is the size I expected would be right for me so I guess Merrell sizing could be described as "expected". Some people may feel the shoes are expensive but, taking into consideration the comfort and quality, my opinion is that they represent good value for money.